Shallow marine bioerosion at Vardø, arctic Norway

Bioerosion was studied at Vardø, northern Norway. Only those substrates that were composed of carbonate (skeletal material) were found to be attacked by organisms. The bioeroding community is dominated by boring algae, which have entered almost every grain. Most surfaces have been rasped by patellid gastropods and some by regular echinoids. Boring sponges, annelids and phoronids are less common, whereas bivalve and, possibly, sipunculid borings were not recorded. The bioeroding community is thus impoverished, in comparison with warm-water communities, and this impoverishment is probably due to the low water temperature. R. G. Bromley, Institut for Historisk Geologi og Palaeontologi, Øster Voldgade 10, DK-1350 København K, Denmark; N.-M. Hanken, Institutt for Biologi og Geologi, Postboks 790, N-9001 Tromsø, Norway. February 15th, 1980. Processes of breakdown of hard substrates by boring and gnawing organisms, collectively known as bioerosion, have received increased attention from biologists and palaeontologists in recent years. The work of these substrate-degrading organisms is eminently preservable in the fossil record as a detailed bioerosion sculpture on the surfaces of shells and rock, and variations in the morphology of the sculpture reflect variations in the constitution and behaviour of the bioerod-ng community. Consequently, a more intimate knowledge of such communities and their bioerosional work will improve our understanding of the processes and refine our use of the sculptures as tools in palaeoenvironmental reconstruction. Several studies have been made in recent years of bioerosion in warm waters (e.g., MacGeachy & Steam 1976, Bromley 1978, Fischer in press), rather fewer in temperate waters (e.g., Farrow & Clokie 1979) and none in Arctic or Antarctic waters. We need many more, detailed studies of bioerosion communities and the results of their work, in many contrasting environments, if we are to gain an understanding of the environmen-tal influence on the morphology of the fossiliza-ble sculpture. We therefore took advantage of an opportunity to sample a sea floor on the north-eastern coast of Norway, about 400 km north of the Arctic Circle.